diff --git a/backend/build.gradle b/backend/build.gradle
index bd7bf50..98f4241 100644
--- a/backend/build.gradle
+++ b/backend/build.gradle
@@ -4,7 +4,7 @@ buildscript {
         mavenLocal()
     }
     dependencies {
-        classpath "org.bdware.bdcontract:simple-ypk-packer:0.3.0"
+        classpath "org.bdware.bdcontract:simple-ypk-packer:0.5.0"
         classpath "org.bdware.bdcontract:ypk-deploy-tool:0.4.0"
     }
 }
@@ -40,8 +40,7 @@ sourceSets {
 dependencies {
     api 'org.apache.logging.log4j:log4j-core:2.17.2'
     api 'org.apache.logging.log4j:log4j-api:2.17.2'
-    implementation fileTree(dir: 'cplibs', include: '*.jar')
-    implementation fileTree(dir: 'cplibs/lib/', include: '*.jar')
+    implementation 'org.bdware.sc:cp:1.5.3'
     testImplementation 'junit:junit:4.13.2'
 }
 
@@ -74,10 +73,10 @@ task copyJar(type: Copy, dependsOn: [":backend:jar", ":backend:copyLibs"]) {
 }
 def reltivePath = "./backend"
 //reltivePath="."
-def currVersion = "1.1.0"
+def currVersion = "1.2.0"
 task grepCP (dependsOn:["copyJar"]){
     doLast {
-        org.bdware.datanet.YPKPacker.grepCPLibWithFilter("${reltivePath}/cplibs/libs","${reltivePath}/build/output/libs","${reltivePath}/grepcp.list")
+        org.bdware.datanet.YPKPacker.grepJarByCPVersion("${reltivePath}/build/output/libs",org.bdware.datanet.CPVersion.cp_1_5_3)
     }
 }
 
diff --git a/backend/buildlibs/simple-ypk-packer-0.3.0.jar b/backend/buildlibs/simple-ypk-packer-0.3.0.jar
deleted file mode 100644
index ea9fb08..0000000
Binary files a/backend/buildlibs/simple-ypk-packer-0.3.0.jar and /dev/null differ
diff --git a/build.gradle b/build.gradle
index 4b9ae9a..07534d3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,8 +2,6 @@ plugins {
     id 'java'
     id 'idea'
 }
-def currVersion = "1.1.0"
-ext.projectIds = ['group': 'org.bdware.sc.contractexample', 'version': currVersion]
 
 tasks.withType(JavaCompile) {
     options.compilerArgs << '-Xlint:none'
@@ -15,8 +13,8 @@ repositories {
 }
 project(':backend') {
     group = "org.bdware.sc.example"
-    version = projectIds.version
     repositories {
+        mavenCentral()
         maven { url 'https://maven.aliyun.com/repository/public' }
     }
 }